DIY Snare Drum LDC Capsule

Long story short, i had a busted capsule which i reskined myself with gold sputered mylar.

I wanted to try two things:

1. Reskin it in c12 style where gold plating covers the whole area. And still use center termination. This was tricky because tightening screws are not allowed to touch gold plating. It was tricky but i made it. Resonant frequency about 1500hz. I made this happen by pure chance.

2. Make bigger gap between membrane and backplate so that the capsule can handle higher SPL (Snare) without doing anything to the circuit. I just used one layer of clear tape on top of existing spacers.

So i made it happen and it works great.

It has about 30db lower sensitivity than stock capsule. It has 120pf capacity. 

It has higher noise floor, but when used on high SPL sources it has huge headroom. So when other condensers clip the signal, this mic has clean transients and therefore same noise floor. So when used on high SPL sources, it actually has the same noise floor level as other condensers because of headroom. It needs same amount of gain like SM57. I used tuned Sterling Audio st51 circuit.

This capsule has less high end than stock. The rest of FR is the same.

Pic #2

What a fun project! Thanks for sharing. Do you have any clips of it in action?

I plan to record snare on next project with it and sm57. Will post results

Where did you get gold sputered mylar?

I don't suppose you have a circuit trace of the ST51? I know they seem basically similar to the 2001/SP1 schematic, but I picked up some variations. How did you tune the circuit, other than the polystyrene input cap?

I have a couple of M-Audio Nova for experimenting, which look to have the exact same board. I biased the FETs, put Banzai K-47 in and increased the electrolytic coupling cap values, and they sound pretty good but it would be great to know more. I have a pretty low polarisation voltage on the capsules too. Good for headroom but a tad noisy.

It is pretty much the same as this guy. Not all component markings match though.

RuudNL said:

Where did you get gold sputered mylar?

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A member here was kind to share a leftover piece he had.

kingkorg said:

It is pretty much the same as this guy. Not all component markings match though.

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Thanks!